Eye of Harmony - The nucleus of
a black hole that was captured by Time Lord Rassilon and
sealed at the center of the planet Gallifrey on the British
sci-fi series DOCTOR WHO/BBC/1963-89.

Introduced in episode No. 14 "The Deadly Assassin," The Eye
of Harmony ("All the power of the Time Lords devolves from
it.") was the product of combined research of two solar
engineers, Omega and Rassilon who wanted to master time and
space and thus create a time travel craft that could moves
effortlessly through the time continuum.

Omega planned on harnessing the energy needed from the
explosion of sun gone nova. His mission succeeded but Omega
was sucked into a parallel universe, never to return.

Using the knowledge gained by Omega's experiments Rassilon
searched the Veil Nebula for the nucleus of a black hole (the
"Eye of Harmony"), collapsed by Omega to harness the raw
energy needed to conquer time.

According to the "Book of the Old Time":

"And Rassilon journeyed into the black void with a great
fleet. Within the void no light would shine and nothing of
that outer nature continue in being except that which
existed within the Sash of Rassilon. Now Rassilon found the
Eye of Harmony, which balances all things that they may
neither flux nor wither nor change their state in any
measure; and he caused the Eye to be brought to the world of
Gallifrey, wherein he sealed this beneficence with the Great
Key. Then the people rejoiced."

The Eye of Harmony was encased into a hexagonal, monolithic
structure ("Rassilon stabilized all the elements of a black
hole and set them in an eternally dynamic equation against
the mass of the planet.") and installed it into the
Panopticon (circular ceremonial room in the Capital).

Now in
control of an inexhaustible source of energy, the Time Lords
were able to travel through time and regenerate their bodies
(up to 12 times) giving them virtual immortality. On the
other hand, if the Eye of Harmony were damaged it could be
the "end not only of this world but of a hundred other
worlds too."

To control the immense power source three items were
required: the Great Key of Rassilon, the Great Rod of
Rassilon; and the Sash of Rassilon ("a technological
masterpiece; it protects its wearer from being sucked into a
parallel universe.").

When the Great Rod is inserted into a
special hole in the floor, The Eye of Harmony rises in the
form of a black monolith. In conjunction with The Matrix,
(the planetary central computer), the Rod, the Sash and the
Key "provide the sum total of Time Lord power."

The remote Eye of Harmony
onboard the TARDIS

A remote Eye of Harmony is installed in the Cloister Room,
the power room of the TARDIS (a time travel craft) so that it can harness the
energy from the main "Eye" located on Gallifrey. The remote
Eye of Harmony is seen in the Fox TV movie, Dr. Who: Enemy
Within (1996).

TRIVIA NOTE: On one episode, The Seventh Doctor (Sylvester
McCoy) encountered an artifact known as the Hand of Omega
that had the ability to manipulate and customize the core of
stars.